Separation of americium(III) from lanthanide by encapsulating hexadentate-ligand

Am(III) is encapsulated in an aqueous phase by a podand-type ligand, N,N,N',N'-tetrakis(2-methylpyridyl)ethylenediamine (TPEN), and is extracted selectively over trivalent lanthanide in an organic phase using nitrobenzene. The extraction of Am(III) using TPEN shows higher selectivity and chemical stability than other conventional ones using nitrogen-donor ligands.